CD8A and primary progressive multiple sclerosis: In summary, motor cortical Nurr1 expression is elevated in multiple sclerosis motor cortex and relates to reduced neuronal loss and CD8+ T-cell inflammation in a cortical-layer specific fashion suggesting a possible neuroprotective role that likely involves numerous mechanisms.21 Future work should be aimed to better understand the mechanisms that alter Nurr1 expression at different stages and forms of multiple sclerosis pathology, such as relapsing–remitting multiple sclerosis and primary progressive multiple sclerosis.